Thermostatic control



R. K. HERTEL THERMOSTATIC CONTROL Flled Nov 26. 1923 Nov. 10,1925- A /Cr/HRD Aaw/mo HERTEL N VEN TOR.

BY WWZM zrw A TTORNEYS matic views to i extending the length thereof, t ere Patented Nov. "10, 1925.

UNITED STATES.

PATENT OFFICE.

RICHARD BONE-AD HIERTEL, OF LOS ANGELES, CALIFORNIA.

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Application filed November 28, 1928. Serial No 677,198.

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This invention relates to a mechanical movement and appertains particularly to a thermostatic control for valves or like apparatu s.

It is the primary object of this invention to provide a simple member, wherein a movement is greatly multiplied and wherein the force at the output end is appreciable. Another object of this invention is to provide a cantilever beam whose bending is effected by difference in the forces simultaneously applied lon itudinally of the beam. A further object 0% this invention is to provide a cantilever movement with means to produce a snap action. In addition to the broader objects of this invention there are certain details of structure, whereby a simple, eflicient, durable,.and positively acting structure is obtained.

These objects together with other objects and correspondingaccomplishments are ob tained by means of the embodiment of my invention illustrated in the accompanying drawing, in which Fig. 1 is a vertical section through a control adapted to be connected to a tank:for the storage of hot water; Fig. 2 is a section as seen on the line '22 of Fig. 1; Fl *3 is a section'as seen on the line 33 of vig. 1' Fig. 4 is a perspective view of a fragment of the control showing the snap catches; Figs. 5 to 8, inclusive, are diagrammatic views showing the principle of operation of the,

snap catches; Fi 9 and 10 are diagramfiiistrate the action of the cantilever; and Fi 11 is a plan view partly in section of anot er form embodying my invention.

.Referringmore particularly to Figs. 1 to 10, inclusive, a waterjacket preferably a castin of aluminum or like metal is indicated' y 12. This jacket has a assa e 13 mg the support 17 is a metal strap an internally threaded nipple 14 communicating with the top thereof and a similar nipple 15 communlcating with the bottom thereof. The structure is such as to permit the circulation of liquid such as water. A

shelf 16 extends outwardly from the bottom" of the jacket and is provided with. an open;- ing to receive a bolt later "described. At the top of the body are supports 17'and 18 having flat faces'to which the cantilevers are adapted to be connected. Mounted, upon the shelf 16 and extending upwardly is a rod 19 preferably formed of steel or metal having a different coefficient of expansion than the metal of which the body is formed. At the top of rod 19 is a threaded stem 20 carrying adjusting nuts for a block 21, whereby the position of the block may be adjusted with res ect to the shelf 16.

ecured to the body so as to rest .against 22. .Dis posed alongside of strap 22 is a strap 23 which is secured at its upper end to the block 21. These straps form pliesof a cantilever beam. The lower ends of the straps are secured together by a rivet 24 so that they can have no relative longitudinal movement at this point. An extension25 is secored to the straps 22 and 23 by the rivet 24. The lower end' of the extension 25 is provided with a laterally extending foot 26 having a toe 27. Secured to the face 18 is a strap 28. Block 21 has secured thereto ,a

strap 29 which lies against strap 28 andforms therewith a two ply cantilever. The

lower ends of the straps 28 and 29'are riveted to ther and have an extension 30 mountetf thereon in a manner similar to extension 25. The lower. end of extension 30 is provided with a foot 31 having a toe 32.

The cantilever beams are disposed so as to lie in planes at right angles to each other, and flexnre of the beams will cause the extensions to move to and from each other.

. Referring to Figs. 9 and 10, the operation of a cantilever beam movement is illustrated. A and B are stra or plys secured to each other at one end a alnst relative longitudinal movement, the ot er ends being free. The straps are such that when no pressure or equal pressures are applied to the straps they will lie in a straight line as shown in Fig. 10. Suppose that a greater pressure is applied to the end of strap A 1n a longitudinal direction as indicated by the arrow in Fig. 9. This will cause a tendency of the top strap to move toward the fixed and of the beam and a restraint thereof by the bottom strap. The effect is the same as in a beam wherein there is tension on one side and compression on the other. The result is that the beam bends. In the structure shown in Figs. 1 to 8 inclusive, the body 12 expands, whereas the rod 19 remaining cold has substantially no expansion. The result is .that there is a difi'erence in pressure. Strap 22 and likewise strap 28 pull up: wardly, while straps 23 and 29 have a pressure in the opposlte direction. This tends to bend the beams. ,Upon the jacket becoming colder, there is contraction and a tendency of the beams to bend in the opposite direction. ,This action causes the extensions to moveto and from each other. In normal cold position, the parts are as shown in Figs. 1, 3 and 4. In'normal or cold position, the feet and toes are in the position shown in Figs. 4 and 5. The beams as they bend move the feet toward each other simultaneously. Toe 32 will reach a v position in front of the path of travel of toe .27 before the-latter can pass in front of.

toe 32. The parts will eventually reach .the

, position shown in Fig. 6. Toe 27, its foot 26 and the beam are thus restrained against movement until toe 32 has reached the position shown in dotted lines in Fig. 6, whereupon toe 27 will sna over to the position shown in Fig. 7. pon the return movement, toe 32 places itself in front of toe 27,

restraining the return of toe 27 until toe 32 has reached the position shown in dotted lines in Fig. 8, whereupon toe 27 and its parts will snap over to theposition shown 1n Fig. 5. This snap action is made use of to control an operatin valve which controls the fiow of as or uel to a burner.

Referring particularly to Fig. 1, a valve case in which there is a valve seat having a port controlling the flow of fuel from one side to the other is indicated by 33. The valve comprises a disk 34 having a stem 35- extending through the casin and abutting extension 25. A compresslon spring 36 tends to'hold valve 34' upon its seat closin the port against the passage of the fue Suppose that the nipples 14 and 15are connected to a hot water tank whose supply of water is heated by a gas burner connected to the valve casing 33. While the water is the arrows in' F igs. 4 to 6 inclusive. After extension 30 has moved a sufiicient distance,

extension 25 snaps outwardly to the position shown in Figs. 7 and 8 ermitting valve 34 to seat and thereby closing off the supply of gas. Upon the water in the boiler decreasing in temperature, the reverse action occurs and the valve is again opened.

In Fig. 11, a split metallic ring is indicated by 37. To the ends of the ring are secured straps 38 and 39 of a cantilever, the outer ends being secured together by a rivet 40. 41 indicates a ring upon which are mounted rollers 42, the ring 41 and rollers 42 serving as a bearing for the expansible ring 37 Obviously expansion and contraction of ring 41 will cause ring 37 to be expanded and thereby cause fiexure of the cantilever at the end, and this may be applied to operate any device desired. For illustration. the ring 41 may be placed about the shell of a cylindrical hot water tank, the heat therefrom causing ring 37 to expand and swing the cantilever. The latter may be connected to a fuel valve operating mechan1sm..

What I claim is:

1. A cantilever movement comprising a plurality of plies. forming a beam, means securing said plies together against lon itudinal movement at one end, a thermaI expansible member secured to one .of said plles so as to. apply stresses lon itudinally thereof, the other of said plies ing held against longitudinal movement.

"2. A thermostatic control comprising a pair of cantilever movements as specified in claim 1, the beams beingformed of resilient material dispose-d with their planes at right angles, extensions onsaid beams disposed to be moved into the path of travel of each other whereby movement of one beam will be restrained by the other until the extension on the last mentioned beam has moved out'of'the path of travel of the extension on the. other beam.

3. A thermostatic control comprisin a pair of cantilever movements as specifie in claim 1, the beams being formed of resilient material and disposed with their planes at right angles and secured to thesame thermally ex ansible member, extensions on said beamsdisposed to be moved into the path of travel of each other whereb movement of one beam will be restrained y the other until the extension on the last mentioned beam has moved out of the path of travel of the e tension on the other beam.

4. A t ermostatic control comprising a, pair of cantilever movements as specified in claim 1, the beams being formed of resilient material and disposed with their planes at right angles and secured to the same thermaily expansible member, extensions on said posed so as to be moved by the restrained beams disposed to be moved into the path beam. of travel of each other, whereby movement In witness that I claim the foregoing I 10 of one beam will be restrained by the other have hereunto subscribed my name this 15 5 until the extension on the last mentioned day of November,-1923.

beam is moved out of the path of travel of the other beam, and a controlled device dis- RICHARD KONRAD HERTEL. 

